轨迹成型法加工光学零件磨床中的微进给电控装置的研究

本文提出了一种在轨迹成型法加工光学零件磨床上实现脆性材料超精密磨削的微进给电控装置。试验表明,在轨迹成型法加工光学零件磨床上应用本装置对光学透镜进行磨削后,工件表面粗糙度可达Ｒａ＝０．０２μｍ,能够达到光学零件精磨的粗糙度要求。     

渐扩切向槽式低压旋流喷流场数值模拟

提出有渐扩切向槽式旋流雾化喷嘴的三维流动数学模型,并采用κ-ε/RNG模型,应用SIMPLE方法数值模拟了在切向槽不同渐扩角度θ时喷嘴内流场特性.结果表明:渐扩切向槽偏转角θ对其流场特性影响较大,偏转角θ为负值时,喷嘴出口处回流较大,θ为较大的正值,喷嘴内流体流动越易形成实心的锥体,但其能量损失增加较大,当偏转角θ=5.8°可实现喷嘴出口处无回流,且流动损失较小,雾化角也比较大.     

基于1149.7标准的测试生成方法研究

单芯片多核设计、片上系统等技术的不断发展为边界扫描技术带来了新的挑战,多扫描拓扑的测试矢量自动生成也成为了研究的重点与热点。基于1149.7标准对测试生成方法进行了研究,包括互连测试矢量、调试应用指令及数据和寄存器配置命令的生成,提出了测试生成的总体框架,以VS2008作为软件平台搭建自动测试生成系统,从数据库中提取目标板信息对寄存器进行配置,生成互连测试矢量或调试数据,最后将生成的信息插入数据库中,在互连测试矢量生成过程中,提出了一种基于边界扫描寄存器的功能来设置网络结点类型的新方法,有效地完成了对复杂网络的测试。     

微正方形角锥棱镜定向反射特性

对微正方形角锥棱镜阵列定向反射器的特性进行了理论研究和模拟。证明了其定向反射特性 ,并利用几何光学方法解决了全反射条件对入射孔径角的限制 ,以及单元有效反射面积对定向反射率的影响问题 ,同时也给出了阵列器件表面反射对定向反射率的影响。为了便于比较 ,也给出了微三角形角锥棱镜阵列定向反射器的单元反射面积。所得结果为微正方形角锥棱镜阵列定向反射器的制作提供了理论依据。     

机器视觉精密测量系统研究

微小孔系的精密测量用传统的手段是难以实现的。以机器视觉为基础,结合计算机图像处理技术可完成这类测量任务。介绍了基于机器视觉的孔系精密测量系统的硬件组成和图像处理算法。以所提出的识别弦端点来确定图像圆心坐标的算法对500根弦的中点坐标进行滤波处理,可使识别误差达到亚像素级。圆心坐标在X和Y方向的标准差均小于4μm,孔系间角度测量标准差小于3″。     

Layer‐by‐layer AuCl3 doping of stacked graphene films

We investigated the effect of layer‐by‐layer AuCl₃ doping on the electrical and optical properties of stacked graphene films. Graphene grown by the chemical‐vapor deposition method on a Cu‐foil was chemically doped by AuCl₃ solution with a concentration of 20 mM. Eight different configurations were prepared and analyzed by using four‐point probe measurements, optical transmittance measurements, scanning electron microscopy, and micro‐Raman spectroscopy to compare the optical and electrical characteristics of the different graphene samples. In our study, the top‐layer doping method was very effective because better performances considering both sheet resistance and optical transmittance were observed from the configurations with the top‐layer doped. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

从微观角度分析电磁感应中的动生电动势和感应电流的形成及能量的转化

以“动电动模型”和“电动电模型”为例,从微观的角度出发,对感应电动势、感应电流的形成以及能量的转化进行分析,目的在于将宏观的认知和微观的内在本质统一起来,以期深入浅出地进行有效教学.     

A novel polythiophene – ionic liquid modified clay composite solid phase microextraction fiber: Preparation,characterization and application to pesticide analysis

This report comprises the novel usage of polythiophene – ionic liquid modified clay surfaces for solid phase microextraction (SPME) fiber production to improve the analysis of pesticides in fruit juice samples. Montmorillonite (Mmt) clay intercalated with ionic liquids (IL) was co-deposited with polythiophene (PTh) polymer coated electrochemically on an SPME fiber. The surface of the fibers were characterized by using scanning electron microscopy (SEM). Operational parameters effecting the extraction efficiency namely; the sample volume and pH, adsorption temperature and time, desorption temperature and time, stirring rate and salt amount were optimized. In order to reveal the major effects, these eight factors were selected and Plackett–Burman Design was constructed. The significant parameters detected; adsorption and temperature along with the stirring rate, were further investigated by Box–Behnken design. Under optimized conditions, calibration graphs were plotted and detection limits were calculated in the range of 0.002–0.667 ng mL⁻¹. Relative standard deviations were no higher than 18%. Overall results have indicated that this novel PTh-IL-Mmt SPME surface developed by the aid of electrochemical deposition could offer a selective and sensitive head space analysis for the selected pesticide residues.     

One‐step synthesis of polymer micro‐tubes tethered by polymer nanowire networks via RAFT polymerization of N,N′‐methylene bisacrylamide xerogel fibers in toluene and ethanol mixed solution

In the mixed solution of toluene and ethanol, polymer micro‐tubes (PMTs) tethered by polymer nanowire networks (PTPWNs) were fabricated facilely via one‐step reversible addition fragmentation chain transfer (RAFT) polymerization by taking N,N′‐methylene bisacrylamide (MBA) xerogel fibers as both template and monomer source. The products were analyzed by FTIR, SEM, TEM, surface area and porosity analyzer, and contact angle tester. The results indicated that PTPWNs were obtained as the sole product at ethanol content of 1.0 wt %. As the content of ethanol increases from 0 to 1.0 wt %, the specific surface area of the products became higher, indicating more polymer nanowire networks (PWNs) on the tubes. At ethanol contents of 1.5 wt % and 2.0 wt %, some particles were also obtained besides PTPWNs. The formation process of PTPWNs was studied by analyzing the products obtained at different reaction time. The results revealed that PTPWNs were formed by two steps, PMTs were formed quickly and then PWNs formed in the solution tethered to the tubes. Moreover, the effect of RAFT agent on the morphologies of the products revealed that PTPWNs could be obtained via RAFT polymerization at suitable dosage of RAFT agent, while polymer particles were generated via conventional free radical polymerization. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1862–1868